I'll try to get this as clear as I can from the proposer of the amendment. Basically it is to put the responsibility on the person who wishes to make the amendment. The burden is on them to prove that the relocation would be in the best interests of the child. It's all about what's in the best interests of the child, and the person who wants to make the relocation is going to have to make that case to the court that it's in the best interests of the child.
On December 5th, 2018. See this statement in context.